Compounds of the norpinane series



Patented Sept. 16, 1947 COMPOUNDS OF THE NORPINANE'SERIES Y Joseph P. Rain, Jacksonville, Fla, assignor, by

, mesne assignments, to The Glidden Company, I I Cleveland, Ohio, a; corporation of Ohio No Drawing Original application January 6, i

1944, Serial No. 517,218. Divided and this application August 12, 1946, Serial No. 690,075

1 Claim.

The present invention relates to new compounds of the pinene group, and to the production of the same, and is a division of my co-pending application, Serial No. 517,218, filedJanuary 6, 1944, for Compounds of the norpinane series and methods of making. V

In my co-pending application Serial No. 399,- 214, filed June 21, 1941, now Patent No. 2,340,294, them is described a new dicyclic primary alcohol and its esters, prepared by condensing nopinene with anhydrous formaldehyde at temperatures from about 100 C. to 250 C. either in the presence or absence of non-resinifying acid catalysts,

The alcohol has the following approximate characteristics B. P. at mm C 110-112 Refractive index (N 1.49-1.493 Density at 25 C 0963-0964 Optical rotation degrees 35 to 37 Since the product is prepared from nopinene and is an alcohol, it will be referred to as nopol.

It, and certain of its derivatives may be considered as apopinene compounds, but since there is no established numbering system for apopinane compounds, the numbering system for norpinane being:

Norpinane Beta pinene, according to this system is 6,6 dimethyl-Z methylene-norpinane, and nopol is B(6,6 dimethyl norpin-2-ene-2-) ethanol.

It has been found that the double bond of nopol may be hydrogenated to produce a new series of compounds of the pinane group. Such compounds do not exhibit the tendency to thermal isomerization shown by nopol and its esters. Also the new compounds do not in general exhibit the pinene reactions which are exhibited by nopol and its esters. The new compounds are therefore more stable. Primary terpene alcohols as well as terpene acid and aldehydes are useful in the medicinal, insecticidal and other fields and the stable products of the present invention are useful in such fields.

Example I This example is illustrative of the preparation of nopol.

50 partsby weight of nopinene, 20 parts of paraformaldehyde, and 1 part of zinc chloride Were heated at 80 to 120 C. The paraformaldehyde gradually dissolves in the course of several hours to give a clear solution. The crude nopol was distilled at108-112 C. at 10 mm. pressure.

In another experiment 408 parts of nopinene and parts of paraformaldehyde'were heated in an autoclave at 200 C. for 3 hours. .The. crude alcohol was distilled under 10 mm. at 110- Example II 322. grams of nopol was hydrogenated at 1000 to 1500 lbs/sq. in. pressure in the presence of 5 grams of Raney nickel catalyst at a temperature 56 grams of hydronopol were dissolved in glacial acetic acid. A cool solution of 55 grams of chromium trioxide in 400 cc. acetic acid and 50 cc. of water was gradually added, the solution being cooled to keep the temperature below 60 C. After the addition of the oxidizing agent was complete, the mixture was warmed to C. and

Calculated to standard conditions of temperature and pressure.

poured into water. This mixture was then extracted with several portions of ether and the ether extracted with 10% NaOH. The soap solution was then extracted with ether to remove neutral materials and acidified. The precipitated oily acid was extracted with-ether and the ether solution evaporated; On cooling-the residue crystallized to give a high yield of the crude hydronopic acid, 6,6, dimethyl norpinane-at-acetic acid. Recrystallization from aqueous methanol gave the pure acid having a meltingpointof 56-58 C. Neutral equivalent-calculated for hydronopic acid, 182.25; found182;8, .1818.

Example IV I-Iydrcnopol was oxidized to thealdehyde by;

ummon" o OH snicmoir HG CH2 H3" Ii oxidation oxidation Juno-00H 11110110- Ho our Ho' CH2- Reduction HOECIB' cm HO 0 '2" cm" 3 r 3 \l \g. OH" 011' CH3 CH3" (III) I. Nopol B (6,6-din1ethyl norpin-2-ene-2) ethanol. II. Hydronopol B (6; 6-dimethyl-norpinanc-2) ethanol. III"; 6, S-dimethyl norpinane-2-acetic acid.

IV. 6, fi-dimethyl norpinane-2-acetaldehyde.

The novel acid shown in Figure III'above is disclosed and claimed in my copending application Serial No. 690,076, filed August 12, 1946.

Having described the invention what is claimed chromium'tri'oxide in water'solution atabout 75 C. The alcohol; 168 "parts; was stirred with 350 parts water containing 40' parts sulfuric" acidi The temperature -of the mixture was" raised to "C; when 67 parts chromium trioxidefin 45-:is: parts water was added." After the reaction was complete th e' mixture was 'extra'ctedwith hexane- 6,6 dimethyl norpin'ane-Z-acetaldehyde.

JOSEPH P. BAIN. 

